IS 4321:1992 Part 1 is the Indian Standard (BIS) for concrete roofing tiles - part 1: plain tiles. This standard lays out the specification for materials, manufacture, dimensions, and testing of plain concrete roofing tiles intended for use on pitched roofs.
Specifies requirements for plain concrete roofing tiles.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Transverse Breaking Load (Plain Tiles) | Minimum average 450 N (no single tile < 400 N) on a 267 mm span. | Method dependent; typically requires a minimum of 600 N to 1200 N depending on class and test method. | EN 490:2011+A1:2017 |
| Water Absorption | Maximum 10% by mass after 24-hour immersion. | No limit specified in the standard; value is declared by the manufacturer, typically under 8% in practice. | EN 490:2011+A1:2017 |
| Water Permeability / Impermeability | No water shall drip from the underside after 24 hours under a static head of water. | Quantitative test. A factor 'I' is calculated based on water absorption over time. For Category 1 (highest), I ≤ 0.5. | EN 490:2011+A1:2017 |
| Dimensional Tolerance (Length) | ± 2% of the specified length. | ± 2 mm of the declared working length (an absolute value). | EN 490:2011+A1:2017 |
| Dimensional Tolerance (Width) | ± 3 mm from specified width. | ± 2 mm of the declared working width. | EN 490:2011+A1:2017 |
| Mass Variation | ± 5% of the specified nominal mass per tile. | Average mass of 20 tiles shall not deviate by more than ±10% from the declared mass. | EN 490:2011+A1:2017 |